Why vegetables in the front? It's a good idea if that's the only yard or the only sunny area you have. Some people worry about car exhaust contaminating vegetables if your house is on a busy street, passers-by stopping to help themselves, or what the neighbours will think. The first worry is probably valid, so wash those vegetables well! Plant some extra for the neighbours, and maybe the last two concerns will take care of themselves. I can't imagine anyone saying a (controlled) tomato plant was ugly once they tasted its fruit...
For your inspiration and enjoyment, here are some links to pages with pictures of vegetables living in plain view of the street:
Of course, when redesigning a yard that is visible to the street, you may want to ensure that you obey municipal and neighbourhood standards. Your city's website is a good place to start looking into that: in Edmonton, I discovered that I can't grow grass or weeds taller than 10 cm, grow noxious weeds of any size (like chickweed or lamb's quarters), or prune your elm tree at the wrong time of year. Other weeds, like dandelions, are not regulated, so you're free to grow those as long as you keep them under 10 cm. Your city, community or condominium association may have different rules, but I think more and more people are realizing that now isn't the time to dump more pesticides on our yards.
So plant away! In walks around my neighbourhood last summer, I remember seeing tomatoes, broccoli, carrots, potatoes and apple trees in plain view, and they all at least looked better than the front yard covered in gray rocks.